1. Field of the Invention
The present invention relates generally to an ink cartridge for ink jet printers. More particularly, the present invention relates to an ink cartridge having an easy ink supplementing function when the supplemental ink is injected into the ink cartridge.
2. Discussion of Related Art
Typically, an ink jet printer is used to print characters or pictures on a plain paper by jetting ink. It uses an ink cartridge to jet ink. Exemplars of the contemporary practice include De Pricjcker et al. (U.S. Pat. No. 5,017,951, Photographic Processing Application With Replaceable Cassette, May 21, 1991) discussing a photographic image-forming apparatus with replaceable cassette including an exposure station. Inside a developing station, a silver halide developer liquid is applied to the imagewise exposed element. Mielnik et al. (U.S. Pat. No. 5,275,310, Vented, Non-reusable, Multi-dose Cartridge, Jan. 4, 1994) discusses a vented cartridge including a container having a top surface, a bottom surface, and side surfaces connected together to define a predetermined volume. A vent tube extends from the top surface and is positioned coaxially with the dip tube. An upper valve is positioned at the upper opening for closing the upper opening when the cartridge is oriented with the top surface facing down. A lower valve is positioned at the lower opening for closing the lower opening when the cartridge is oriented with the top surface facing up.
Harrold (U.S. Pat. No. 5,356,037, Lift And Drop Ratchet Stick Dispenser, Oct. 18, 1994) discusses a dispenser for liquids or solids. It includes a main hollow housing with side walls, an open base and an open top. A portion of the housing is tapered downwardly so as to permit upward movement and restrict downward movement of a displacable plate located within the housing. Plumadore (U.S. Pat. No. 4,515,463, Inclined Toner Flow Control System For Developing An Electrostatic Latent Image Upon An Electrophotographic Film, May 7, 1985) discusses a toner control system for liquid toner within a camera and processor apparatus. The film and electrode define a toner flow channel therebetween, whereby the flow of the liquid toner through the channel is able to be controlled and uniformly distributed over the electrode and film. In addition, gravity discharge of the toner from the channel is able to be accomplished without the need for special sealing devices to confine the toner within the toner cell. The controlled flow of the toner within the channel eliminates the need for substantial negative pressure or vacuum suction systems normally employed in conjunction with vertically oriented toner channels. From my study of these exemplars of the contemporary art, I find that there is a need for an improved and effective ink cartridge in which even when ink overflows, the ink does not externally run over but is sent into the ink cartridge.